Nailfold capillary microscopy in patients with anticardiolipin antibodies: a case-control study

This case-control study was undertaken to determine whether anticardiolipin antibodies (ACA) are responsible for particular abnormalities in nailfold capillary microscopy (NCM). Cases comprised 33 consecutive patients positive for ACA (24 women and 7 men). Controls comprised the same number of ACA-negative patients, with the same sex ratio, the same diagnosis and the most similar duration of disease possible. Clinical data, serum samples and NCM recordings were obtained from all patients and controls.

In each group, 22 patients had connective-tissue-related disorders and 11 various other diseases. In ACA-positive patients, the mean IgG ACA titre was 39 +/- 58 IgG phospholipid units. Cases and controls displayed various cutaneous manifestations. In ACA-positive patients, there were Raynaud's phenomenon (54%), cutaneous vasculitis (24%), scleroderma changes (18%), photosensitivity (9%), a history of digital gangrene (6%), malar rash (6%), acrocyanosis (6%), chilblains (3%), livedo reticularis (3%) and purpura (3%). Cases and controls exhibited numerous NCM abnormalities. In ACA-positive patients, they included haemorrhages (54%), oedema (24%), bushy capillaries (21%), disordered capillaries (18%), capillary bed disorganization (12%), capillary rarefaction (9%), giant capillaries (6%) and 'desert areas' (3%). There were no correlations between the ACA titres on the one hand and the number of cutaneous manifestations or NCM abnormalities on the other.

ACA-positive patients frequently exhibit clinical skin lesions and abnormal NCM. In this study, these lesions and NCM abnormalities resembled those of the matched ACA-negative controls.